Many implantable medical devices, such as infusion devices, neurostimulators, pacemakers and defibrillators, include multiple components disposed within a hermetically sealed housing to protect the components from the environment of the human body. Placement of the components within the housing is important from both manufacturing and functional perspectives. For example, it is desirable for the components to be placed in the housing in a space efficient manner so that the overall size and volume of the device is kept small for purposes of patient comfort. In addition, the number of steps required in the manufacture of an implantable medical is a concern, as each step requires careful attention, and time. Efforts to reduce or simplify the complexity, cost, and time of manufacturing and the assembly process directly impact the cost of the implantable medical device for patients. More simple and cost-effective device assembly processes for implantable medical devices are desirable.
One development that has reduced the size of implantable medical devices is the use of rechargeable batteries. Larger cells are needed if the batteries are not rechargeable to provide sufficient power to operate the device over an extended period of time. With rechargeable batteries, small cells that deplete more rapidly may be employed, as they can be recharged. However, rechargeable batteries present some manufacturing design concerns. For example, rechargeable batteries expand during the recharging process, and room for such expansion should be accounted for in the design. In addition, expansion and contraction of the battery during use may cause the battery to come loose or compromise its electrical connections unless adequately accounted for in the device design.